Coronary artery disease remains the leading cause of morbidity and mortality in Western societies. A number of approaches have been developed for treating coronary artery disease. In less severe cases, it is often sufficient to merely treat the symptoms with pharmaceuticals or to treat the underlying causes of the disease with lifestyle modification. In more severe cases, the coronary blockage can be treated endovascularly using techniques such as balloon angioplasty, atherectomy, laser ablation, stents, and the like. In cases where these approaches have failed or are likely to fail, it is often necessary to perform a coronary artery bypass graft procedure.
The coronary artery bypass graft procedure traditionally required a heart-lung or cardiopulmonary bypass. Due to the risks incurred during cardiopulmonary bypass, beating heart bypass surgery techniques have been developed to allow coronary artery bypass without cardiopulmonary bypass. Several systems are presently available which attempt to immobilize epicardial tissue in the immediate vicinity of an anastomosis site through a pressure stabilizer employing a simple mechanical fork. Such a device stabilizes the heart by pressing a fork downwards onto the heart surface. The fork is typically mounted to an elongated arm, which in turn is typically mounted to a retractor, holding the patient's ribs apart to create an operative window. Angular movement of the arm relative to the retractor in some cases is accomplished by means of a turret, which may be clamped in its desired rotational position. Longitudinal movement of the arm relative to the retractor is typically allowed as well, and clamping mechanisms are typically provided to allow clamping of the arm to the turret and locking of the fork relative to the arm. Exemplary pressure stabilization devices are disclosed in U.S. Pat. No. 6,876,332, issued to Looney and U.S. Pat. No. 6,036,641, issued to Taylor, et al., both incorporated herein by reference in their entireties.
Suction stabilization systems, such as the Medtronic Octopus® Tissue Stabilizer (available from Medtronic, Inc., Minneapolis, Minn. USA), instead employ a comparatively long, flexible, articulating arm carrying a pair of suction paddles or pods at its distal end. During use, the arm is typically secured to a retractor, holding the patient's ribs apart to create an operative window. The pods are placed on either side of the anastomosis site and suction is applied to grip and immobilize the surface of the heart. Thereafter, tension is applied along the length of the arm to lock the arm in its position and to lock the position of the pods relative to the Arm. In Medtronic's device, is generally disclosed in pending U.S. patent application Ser. No. 09/396,047, filed by Boone, et al. on Sep. 15, 1999, for a “Method And Apparatus For Temporarily Immobilizing A Local Area Of Tissue”, incorporated herein by reference in its entirety. In this device, a single knob, mounted to the proximal end of the arm, is employed to lock the arm in position and additionally to spread the pods somewhat, slightly stretching the heart's surface to provide additional stabilization of the heart surface. In such devices, all adjustment of the arm relative to the retractor is accomplished by varying the configuration of the flexible arm, prior to locking it in its desired position. Other examples of suction stabilization devices are disclosed in U.S. Pat. No. 6,113,534, issued to Koros, et al., U.S. Pat. No. 6,007,486, issued to Hunt, et al, U.S. Pat. No. 5,836,311, issued to Borst, et al. and U.S. Pat. No. 5,727,569, issued to Benetti, et al., all incorporated herein by reference in their entireties.
In conjunction with stabilization devices, suction retractors are often employed to position the heart to allow access to the desired anastomosis site. The Medtronic Starfish™ device and the Guidant Axius™ Expose™ device are examples of commercially available suction retractors. These devices employ a single, larger suction pod to engage the heart, typically in the vicinity of the heart apex. The suction pod is carried by a flexible arm, which, like the suction stabilizers discussed above, also may be locked into a desired configuration by tension applied along their length. The application of tension to the arm may also serve to lock a carrier for the suction pod relative to the arm to fix the suction pod in a desired orientation relative to the arm, as in the Guidant device. The Medtronic device is described in pending U.S. patent application Ser. No. 09/679,294, filed Jun. 12, 2001 by Keogh, et al. for a “Method and System for Organ Positioning and Stabilization, incorporated herein by reference in its entirety. The Guidant device is described in the brochure “Axius™ Expose™ Device, Instructions for Use, Guidant Corp., 2001, P/N 30462, Rev. A, also incorporated herein by reference in its entirety. Other suction retractors are described in U.S. Pat. No. 6,019,772, issued to Spence, et al. and PCT Publication No. WO 01/17437 by Peng, both also incorporated herein by reference in their entireties.